Prior art refers to traditional sewer systems for use in sewer/waste water and surface water. Fluid from inlets are collected and guided, typically via one or more cesspools and collection tanks and further to an outlet where the fluid typically gets treated, such as a sewer disposal plant, before it is drained and deposited at appropriate places. Between inlets, cesspools and treatment plants are used pipes to connect, possibly also manifolds or branching-pieces connecting two or more pipes together to one pipe.
The principle is based upon liquid flowing by its own weight, and is called “gravity flow” (self-falling). Cesspools, pipes and manifolds are open and allow air to be let into the sewer system and thereby limit the amount of liquid that the system can handle. In addition, the use of cesspools presents a risk of liquid flowing from parts of a system at higher altitude flowing out from a lower inlet.
From prior art FR2567934 is known a sewer system comprising at least one cesspool. Reference is also made to WO2000/6844 regarding a cesspool suitable to clean sewer pipes. Further, DE3617284 regards control of draining of tanks or sewer pipes. Reference is also made to an ejector device in a water supply pipe for generating suction in a branch line. Finally, WO1998/28499 regards gathering lines and daily water wells.